Abstract: An inseparable railroad train unit comprises three cars and is adapted for use selectively as a self propelled unit and as an after-coupled unit in a passenger train of the through-passage type. At least the front end of the train unit has a central window equipped door, behind which a driver's desk is provided, and around the door opening is provided a forwardly protruding elastomeric gable member, which provides for an aerodynamically advantageous shape of the front. When the train unit is after-coupled to a similar unit, the driver's desk is stowed away laterally, and the front door is opened for providing the required through passage. The elastomeric gable member now acts as a sealing and shielding element surrounding the passageway between the car and the preceding car.